Organic light-emitting devices (OLEDs) have many advantages over other display technologies. One of the advantages of OLEDs is the ability to fabricate them on flexible substrates. Other advantages of OLEDs include their efficient, emissive, solid-state nature and the absence of viewing-angle effects. However, many OLEDs on flexible substrates exhibit inadequate lifetimes due in part to lack of effective encapsulation of these OLEDs to preclude the ingression of water and oxygen. Accordingly, there is an urgent need in the field for effective protective barriers for OLEDs on polymer substrates to provide sufficient protection against the ingression of water and oxygen, thereby ensuring satisfactory lifetimes for these devices.